The elements of navigation : containing the theory and practice, with all the necessary tables, to which is added, a treatise of marine fortification ... (1754)
Robertson, J. (John), 1712-1776, Adams, Charles Francis, 1807-1886, former owner. BRL, Adams, John, 1735-1826, former owner. BRL, Boston Public Library) John Adams Library BRL · London : Printed for J. Nourse ... · leaf 99
cut each ether $ their commonfeclion (bd) will be a right line* A *> Dem. For if it be not, draw a right line deb in the plane ab, from thepoint d to the point b ; alfo draw a right line dfb in the plane bc. Then two right lines deb, dfb, have the fame terms, and include afpace or figure which… … 284. THEOREM XXXIII. If two planes (ab, cd), which are both perpendicu*lar to a third plane (ef), -<& cut one another; their in-ter-feclion (hg) is at right angles to that third plane (EF). Dem. For the common fe&ion of ab and cd is a right line (gh) (283):Alfo hb, hd, are thefe&ions…
Navigation · Nautical astronomy · Fortification
Internet Archive · Boston Public Library · Public Domain Mark 1.0. Free to use for anything.
![An illustration from Examen dv livre des Recreations mathematiqves, & de ses problemes en geometrie mechanique, optique & catoptrique [du J. Leurechon] Où sont aussi discutées & restabiles plusieurs experiences physiques y proposées (1639)](https://img.insideoutlibrary.com/img/200/ia-examendvlivredes00mydo-83-17.webp)
